I am trying out an Acer Aspire One netbook. It is one of the cheaper ones, but its performance is similar to all the other ones out there. It is available either with Linux or Windows XP but I wanted to see how Windows 7 would run on it.
I installed Windows 7 Build 7000 from a DVD (connected via USB) and was pleasantly surprised to find everything apparently working when it had finished. The wireless network adaptor did not work but rebooting fixed it and brought to light a problem, which I have not yet solved: the WLAN works half the time. If it is working, reboot and the WLAN hardware will not be configured and will show up as Ethernet adaptor. Reboot again and it be configured as an Atheros AR5007EG Wireless Network Adaptor.
You can install a Synaptics trackpad Vista driver in order to get some additional functionality, but it works fine without it. The Aspire One has two memory card slots, which do require a driver to work. The memory card reader controller is a JMicron JMB38X and you can find a Vista driver here.
Note that the latest BIOS is version 3309 and can be downloaded here. However, for some ridiculous reason, the only way to update it is by booting the machine into DOS from a bootable floppy. Fortunately, there are instructions on this site on how to create a bootable USB flash drive for this purpose.
Overall, Windows 7 (and Office 2007) work well on this little machine.